1. The PHILCO Phorum
  2. Various and Sundry Categories
  3. Test Equipment
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Threaded Mode
RCA WV-98c
morzh
Odobenus rosmarus
*****
Posts: 15,850
Threads: 555
Joined: Oct 2011
City: Jackson, NJ
#31

11-10-2024, 09:22 PM
strange. It should have more even to the GND, and the GND is 1M to the case.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Find
daveone23
Member
***
Posts: 96
Threads: 20
Joined: Jun 2024
City: tampa State, Province, Country: florida
#32

11-11-2024, 08:30 AM
Are you saying if I measure ohms from the ground lead to case it should be 1m ohms? That low resistance tells me there is a leak to ground, right?
(This post was last modified: 11-11-2024, 09:03 AM by daveone23.)
Find
morzh
Odobenus rosmarus
*****
Posts: 15,850
Threads: 555
Joined: Oct 2011
City: Jackson, NJ
#33

11-11-2024, 08:47 AM
Well, in the sch you provided (there is something missing at the very bottom, but I think it is GND), the sole connection to the case shown is the 1M resistor R31, which is used to bring the case and the GND under the same potential.
Unless I am missing something.

Of course there is a cap across that R31. And it could be bad. Or, again, we are missing something.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Find
daveone23
Member
***
Posts: 96
Threads: 20
Joined: Jun 2024
City: tampa State, Province, Country: florida
#34

11-11-2024, 09:17 AM
I guess I need to look at r31 and C7.


Attached Files Image(s)
   
Find
morzh
Odobenus rosmarus
*****
Posts: 15,850
Threads: 555
Joined: Oct 2011
City: Jackson, NJ
#35

11-11-2024, 09:25 AM
That too.
There might be other things.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Find
daveone23
Member
***
Posts: 96
Threads: 20
Joined: Jun 2024
City: tampa State, Province, Country: florida
#36

11-11-2024, 04:28 PM
Interesting readings, r31 common ground to case bounced to 1meg on analog meter, r31 common to case bounced to 1meg. R31=1meg.  Across c7, which is common to case with a parallel resistor = 40k ohms steady.
(This post was last modified: 11-13-2024, 11:41 AM by daveone23.)
Find
daveone23
Member
***
Posts: 96
Threads: 20
Joined: Jun 2024
City: tampa State, Province, Country: florida
#37

11-11-2024, 06:40 PM
My resistance readings are not even close. Worried about pins 1 and 6. Even though they are off, the meter works on dc 50v and higher.
(This post was last modified: 11-13-2024, 11:41 AM by daveone23.)
Find
morzh
Odobenus rosmarus
*****
Posts: 15,850
Threads: 555
Joined: Oct 2011
City: Jackson, NJ
#38

11-11-2024, 07:20 PM
>>r31 common ground to case bounced to 1meg on analog meter, r31 common to case bounced to 1meg.

Would you re-read and correct?
This does not make sense.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Find
morzh
Odobenus rosmarus
*****
Posts: 15,850
Threads: 555
Joined: Oct 2011
City: Jackson, NJ
#39

11-11-2024, 07:21 PM
Check all your caps. Even ceramics. I am not sure what is going on.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Find
morzh
Odobenus rosmarus
*****
Posts: 15,850
Threads: 555
Joined: Oct 2011
City: Jackson, NJ
#40

11-13-2024, 10:24 PM
Just occurred to me: what if you have a power transformer leak? From a, say, secondary to the case. If it is bolted to teh case.
Not sure how to better check it.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Find
daveone23
Member
***
Posts: 96
Threads: 20
Joined: Jun 2024
City: tampa State, Province, Country: florida
#41

11-14-2024, 09:46 AM
Thats a good thought but the secondary does go to ground via R30 27k resistor.
Find
morzh
Odobenus rosmarus
*****
Posts: 15,850
Threads: 555
Joined: Oct 2011
City: Jackson, NJ
#42

11-14-2024, 10:26 AM
Yes.....it would connect GND to case, and you do have 1MOhm.....

I am not sure how the wiper has resistance to the case.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
(This post was last modified: 11-14-2024, 10:29 AM by morzh.)
Find
daveone23
Member
***
Posts: 96
Threads: 20
Joined: Jun 2024
City: tampa State, Province, Country: florida
#43

11-15-2024, 03:56 PM
From now on iam using an analog meter. R31 removed is 1 meg and c7 .01 but chassis to common is 600k. Why is that?
Find
morzh
Odobenus rosmarus
*****
Posts: 15,850
Threads: 555
Joined: Oct 2011
City: Jackson, NJ
#44

11-15-2024, 04:22 PM
Are you saying the Chassis to GND became LESS when you removed the R31?
And we are sure the C7 and other caps are not leaking?
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Find
daveone23
Member
***
Posts: 96
Threads: 20
Joined: Jun 2024
City: tampa State, Province, Country: florida
#45

11-15-2024, 05:57 PM
Yep, hunting down the source. Will get back to you. Thanks
Find
« Next Oldest | Next Newest »




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
38-10T chassis Restoration begins
Hi Richard, I used to build houses and we used a lot of those gold flake counter tops. We even used gold flake ceramic t...dconant — 11:11 AM
38-10T chassis Restoration begins
Hello Guys, Don't mind my 1950s kitchen countertop and funny thing about that countertop it has little what looks like ...radiorich — 10:53 AM
38-10T chassis Restoration begins
Hello Dconant, Very funny but here is Photo of my Gemoro ultrasonic cleaner ! Arran , I have not had any issues eith...radiorich — 10:48 AM
Philco 60 Squealing
Radio is playing right now and sounding good.dconant — 08:54 AM
38-10T chassis Restoration begins
I don't think it is as critical as some would think. I've washed chassis, typically on hot days during the summer time, ...Arran — 07:51 AM
Rusty Tuning Condenser
I would try something like Evaporust, or a similar product, there is a guy on Y.T that does this with aluminum fined tun...Arran — 05:14 AM
Rusty Tuning Condenser
Be careful with aluminum vane caps. I did that, with dishwasher; it dulled the whole thing, which became grey. No, no,...morzh — 10:19 PM
Rusty Tuning Condenser
Hello Rob. I've also heard of soaking the tuning cap in automatic transmission fluid. This was an old trick we used to...GarySP — 06:14 PM
Rusty Tuning Condenser
Gary, I once had a tuning cap that had a thick coat of kitchen grease and grime. So I had heard about brake cleaner bei...RodB — 06:03 PM
Rusty Tuning Condenser
I've put tuning caps with mica removed and vanes wide open in the dishwasher and ran through a cycle. When the dishwash...GarySP — 05:42 PM

[-]
Who's Online
There are currently no members online.

>
  1. The PHILCO Phorum
  2. Various and Sundry Categories
  3. Test Equipment